Crosslinked copolymers and ophthalmic devices amde from vinylic macromers containing perfluoropolyalkylether and polyalkylether segments and minor amounts of vinylic comonomers

ABSTRACT

The instant invention relates to crosslinked copolymers of (a) vinylic macromers containing perfluoropolyalkylether and polyalkylether segments with (b) minor amounts of vinylic comonomers and ophthalmic devices such as intraocular implants and contact lenses and particularly soft hydrogel contact lenses made therefrom.

This is a divisional of U.S. patent application Ser. No. 296,169, filedon Jan. 11, 1989, now U.S. Pat. No. 4,929,692, issued on May 29, 1990.

BACKGROUND OF THE INVENTION

The instant invention relates to crosslinked copolymers of (a) vinylicmacromers containing perfluoropolyalkylether and polyalkylether segmentswith (b) minor amounts of vinylic comonomers and ophthalmic devices suchas intraocular implants and contact lenses and particularly softhydrogel contact lenses made therefrom. These devices possess anadvantageous blend of desirable properties including (a) high oxygenpermeability, (b) excellent wettability, (c) high mechanical strength,(d) flexibility, (e) optical clarity, (f) biocompatibility, and (g) arecapable of being sterilized in boiling water. Theperfluoropolyalkylether segments provide in large part the high oxygenpermeability, the polyalkylether segments provide the wettability andthe unique polymer structure provides the desired mechanical properties.

In general, most existing hydrogel soft contact lens materials are basedon HEMA, also known as hydroxyethyl methacrylate or as ethylene glycolmonomethacrylate, with one or more optional comonomers as described inU.S. Pat. Nos. 2,976,576, 3,841,985 and 3,985,697. Other hydrogels basedon N-vinylpyrrolidone copolymers and acrylamide copolymers are disclosedin U.S. Pat. Nos. 3,639,524 and 3,929,741. These prior art hydrogelpolymers generally suffer from several inherent problems (a) relativelyweak mechanical strength, (b) low dissolved oxygen permeability or acombination of both. Most lenses are made by either of two procedures,one requiring costly lathing and polishing steps and the other usingdelicate spin casting techniques where polymerization, crosslinking, andshaping are done simultaneously.

Perfluoropolyalkylether segments have been proposed as constituents ofcontact lens materials. For example:

In U.S. Pat. Nos. 3,940,207 and 3,944,347 poly(perfluoropropylene oxide)oils were incorporated into a contact lens matrix. However, in this casethe material is extremely hydrophobic and the oil can leach out.

In U.S. Pat. No. 3,542,461 a terpolymer is formed fromhexafluoroacetone, tetrafluoroethylene and ethylene. The polymers soformed are in general of insufficient wettability and some are not ofcomplete clarity.

In U.S. Pat. No. 4,440,918 and Eur. Pat. Appl. No. EP0084406, it isdisclosed to make ophthalmic devices such as contact lenses fromtelechelic perfluorinated polyether polymers. These polymers areextremely hydrophobic and require the addition of a hydrophiliccomonomer or surface treatment to improve wettability. Although anincrease in wettability is described, the increase is generallyinsufficient to overcome the hydrophobic nature of theperfluoropolyether segments and to provide adequate patient comfort.Also, surface treatments are generally not permanent.

In Japanese Patent Applications Nos. 61-111308, 61-112047, 61-123609,61-126052, 61-285425 and 61-285426, are described perfluoroalkylethercontaining polymers useful as raw materials for oxygen permeable devicesand medical devices such as contact lenses. These polymers are of poorwettability and require the addition of hydrophilic comonomers orsurface treatments to obtain the requisite wettability. Also, some ofthese materials have a tendency of being yellow in color.

In Eur. Pat. Appl. No. EP0253515 is described the use of aperfluoropolyether monomer for use in soft contact lenses. Thesematerials are also extremely hydrophobic and need a substantial quantityof hydrophilic comonomer to obtain wettability and in addition requirethe inclusion of the N-vinylpyrrolidone comonomer to obtain clarity.

Perfluoropolyether monomers useful in condensation polymerizations aredisclosed in Eur. Pat. Appl. No. EP0084406 and Jap. Pat. Appl. No.61-166834. In the Japanese application a perfluoropolyether polytriazinematerial derived from a multivalent nitrile polymer is used in gaspermeating materials such as contact lenses. These materials appearyellow in color. The perfluoropolyether monomers of both patentapplications are hydrophobic and require the presence of a hydrophiliccomonomer. In addition, condensation polymers are generally of poorquality for contact lens use because, for example, of the difficulty inobtaining a sufficiently high molecular weight with the concommitantdesirable physical properties.

In Eur. Pat. Appl. No. EP0273449 is described aqueous dispersions offluorinated polyurethanes containing ionic groups and their use fortextile coatings.

It is an object of the present invention to overcome the disadvantagesof the prior art by providing a modified perfluoropolyalkylethermacromer which is inherently hydrophilic. This is accomplished by use ofa block structure where the perfluoropolyalkylether block provides asubstantial portion of the oxygen permeability properties and thepolyalkylether block provides the hydrophilicity.

It is a further object to provide aperfluoropolyalkylether/polyalkylether macromer which can be crosslinkedin the presence of a minor amount of another vinylic comonomer to form asoft water-swellable hydrogel contact lens having (a) high oxygenpermeability (b) good wettability (c) high mechanical strength (d)flexibility (e) optical clarity, (f) biocompatibility and (g) capable ofbeing sterilized in boiling water. It is a further object of the presentinvention to provide medium to high water content contact lensesobviating, or substantially reducing, the drawbacks of the prior art.

It is a further object of the present invention to provide a method ofpreparing such contact lenses by crosslinking a vinylicperfluoropolyalkylether/polyalkylether macromer with a minor amount ofanother vinylic comonomer in a solvent in a mold, such as a spin castmold or a static cast mold, and equilibrating the resulting solventswollen crosslinked contact lens in an aqueous medium.

A further object of the invention is to provide a method of correctingvisual defects in the form of refractive errors by fitting to thepatient's eye in need of the same, a corrective contact lens of suchpolymer.

These and other objects of the invention are apparent from the followingdetailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The instant invention provides a crosslinked polymer which is theaddition polymerization product of (a) a macromer containingperfluoropolyalkylether and polyalkylether segments and ethylenicallyunsaturated moieties, having the formula I, more specifically as seen informulas Ia to Id,

    E--T--L--Q--X--Z--X--Q--L--T--E,                           (Ia)

    E--T--L--Q--X--Z--X--Q--L,                                 (Ib)

    E--T--L--Q--X--G--X--Q--L--T--E, or                        (Ic)

    E--T--L--Q--X--G--X--Q--L                                  (Id)

wherein

Z is --(C_(a) F_(2a) O)_(b) --CF₂ --, where

a is 1 to 4, b is 2 to 200;

X is a direct bond, --CH₂ --, --CH₂ OCH₂ CHOHCH₂ --, --CH₂ (OCH₂CH₂)_(y) -- or carbonyl where y is 1 to 10 and where in each case thecarbon atom is attached to Z or G;

Q is a direct bond or --ACONH--R--NHCO-- where A is oxa or imino and Ris a divalent aliphatic group having from 2 to 14 carbon atoms, adivalent 5-or 6-membered cycloaliphatic group having 5 to 14 carbonatoms or an arylene group having 6 to 14 carbon atoms;

L is --A(C_(m) H_(2m) O)_(n) C_(m) H_(2m) AY-- or L₁ where Y is a directbond or H and m is 2 to 4 or mixtures thereof and n is 5 to 100, where Ais attached to Q;

T is --CONH--R₅ A-- or --CONH--R--NHCOOR₅ A-- or --CONH--R--NHCO--A-- or--R₅ A-- or direct bond where the carbonyl group is attached to L, whereR₅ is alkylene or hydroxy-substituted alkylene of 2 to 15 carbon atomsand R is as above; ##STR1## where R₁ is hydrogen or methyl, and

R₂ is hydrogen, methyl or --COOR₃

where

R₃ is hydrogen or alkyl of 1 to 4 carbon atoms with the proviso that,

when

R₁ is methyl, R₂ is hydrogen, R₄ is hydrogen or methyl and

G is --(C_(a) F_(2a) O)_(b) --CF₂ [CH₂ --OCONH--R--NHCOOCH₂ CF₂ (OC_(a)F_(2a))_(b) ]_(x) or

--(C_(a) F_(2a) O)_(b) --CF₂ [CH₂ --NHCONH--R--NHCONHCH₂ CF₂ (OC_(a)F_(2a))_(b) ]_(x)

where

x is 1 to 3;

L₁ is --A(C_(m) H_(2m) O)_(n) [C_(m) H_(2m) ACONH--R--NHCOA(C_(m) H_(2m)O)_(n).sbsb.1 ]_(z) C_(m) H_(2m) AY

where n₁ is 5 to 100, z is 1 to 10 and Y is a direct bond or H; and

(b) a vinylic comonomer selected from

(i) hydrophilic monomers selected from hydroxy-substituted lower alkylacrylates and methacrylates, acrylamide, methacrylamide, C₁ -C₂ loweralkyl acrylamide and methacrylamide, ethoxylated acrylates andmethacrylates, hydroxy substituted lower alkyl acrylamide andmethacrylamide, hydroxy substituted lower alkyl vinyl ethers, sodiumethylene sulfonate, sodium styrenesulfonate,2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrole,N-vinylsuccinimide, N-vinylpyrrolidone, 2- and 4-vinylpyridine, acrylicacid, methacrylic acid, amino (by amino including quaternaryammonium), - monoloweralkylamino- or diloweralkylamino- lower alkylacrylates or methacrylates and allyl alcohol;

(ii) hydrophobic monomers selected from C₁ to C₁₈ alkyl acrylates andmethacrylate, C₃ to C₁₈ alkyl acrylamides and methacrylamides,acrylonitrile, methacrylonitrile, vinyl C₁ to C₁₈ alkanoates, C₂ to C₁₈alkenes, C₂ to C₁₈ haloalkenes, styrene, C₁ to C₆ alkyl styrenes, vinylalkyl ethers wherein the alkyl portion has 1 to 6 carbon atoms, C₃ -C₁₂perfluoroalkyl ethyl thiocarbonylaminoethyl acrylates and methacrylates,C₃ -C₁₂ fluoroalkyl acrylates and methacrylates, acryloxy andmethacryloxy-alkyl-siloxanes, N-vinylcarbazole, C₁ -C₁₂ alkyl esters ofmaleic, fumaric, itaconic, and mesaconic acids;

(iii) polyreactive crosslinking agents such as allyl methacrylate,diallyl itaconate, monoallyl itaconate, diallyl maleate, diallylfumarate, diallyl succinate, diallyl phthalate, triallyl cyanurate,triallyl isocyanurate, diethylene glycol bis-allyl carbonate, triallylphosphate, triallyl trimellitate, allyl ether, N,N-diallylmelamine;vinyl compounds, e.g. divinyl benzene, N,N'-methylene-bis-acrylamide,ethylene glycol dimethacrylate, neopentylglycol dimethacrylate,tetraethylene glycol dimethacrylate, hexamethylene-bis-maleimide,divinyl urea, bisphenol A bis methacrylate, divinyl adipate, glycerintrimethacrylate, trimethylolpropane triacrylate, trivinyl trimellitate,1,5-pentadiene, 1,3-bis(4-methacryloxybutyl) tetramethyl disiloxane,divinyl ether, divinyl sulfone; and the dimethacrylate formed byreacting perfluoropolyalkylether dimethanol or poly(ethylene glycol)with two moles of isocyanatoethyl methacrylate; and (iv) mixtures of(i), (ii) and (iii).

Preferably the macromer is of formula Ia.

In the foregoing perfluoropolyether portion, Z, of the macromonomer, ais preferably 1 or 2, and b is preferably 3 to 50.

X is preferably --CH₂ -- or --CH₂ (OCH₂ CH₂)_(y) -- where y is 1 or 2.

A is preferably oxa.

Q is preferably --OCONH--R--NHCO-- where R is a radical derived fromdiisocyanates including hexane-1,6-diisocyanate,trimethyl-hexane-1,6-diisocyanate, tetramethylene-diisocyanate,phenylene-1,4-diisocyanate, toluene-2,4-diisocyanate,toluene-2,6-diisocyanate, m- and p-tetramethylxylene-diisocyanate,isophorone-diisocyanate and cyclohexane-1,4-diisocyanate, and mostpreferably isophorone-diisocyanate.

L is preferably a polyalkylether, --O(C_(m) H_(2m) O)_(n) C_(m) H_(2m)O-- where m is 2 or a mixture of 2 and 3, more preferably m=2 and n is10-50. Where m is a mixture of 2 and 3, the mixture contains a majorproportion of m=2.

T is preferably --CONH--R₅ A-- where R₅ is preferably ethylene. Where Tis --CONH--R--NHCOOR₅ A--, R is preferably a radical derived fromisophorone diisocyanate and R₅ is preferably ethylene. ##STR2## where R₁is preferably methyl and R₂ is preferably hydrogen. Where E is ##STR3##Where E is ##STR4## R₁ is preferably methyl and R₂ is hydrogen.

Where G is present, x is preferably 1, and R is preferably a radicalderived from isophorone diisocyanate.

Where L₁ is present, A is preferably oxa, R is preferably a radicalderived from isophorone diisocyanate, z is preferably 1 to 5 andpreferably n=n₁.

The vinylic macromonomers of formula I can be prepared by methods known,per se.

For example, the perfluoropolyalkylether/polyalkylether containingdivinylic macromonomers of formula Ia can be prepared in a three-stepsequential synthesis. In the first step, a perfluoropolyalkyletherdialkanol of the formula HOCH₂ --C_(a) F_(a) O)_(b) --(CF₂)--CH₂ OH isreacted with two moles of a difunctional reactive diisocyanate of theformula OCN--R--NCO in the presence of a urethane catalyst to form thecorresponding reactive group containing endcapped derivative, Z₁--NCO)₂, where Z₁ is a moiety containing a perfluoropolyalkylethersegment. In the second step, the resulting endcappedperfluoropolyalkylether derivative Z₁ --NCO)₂ can then be reacted withtwo moles of a polyoxyalkylene diol of the formula HO--(C_(m) H_(2m)O)_(n) H preferably in the presence of a conventional aprotic solvent ata temperature between about -10° C. to about 100° C., to form thecorresponding polyalkylether-perfluoropolyalkylether-polyalkyletherderivative of the formula ##STR5##

In the third step, this triblock diol can be then reacted with two molesof reactive group containing vinylic monomer, wherein the reactive groupis an isocyanate, say, of the formula ##STR6## wherein R, A, R₁, and R₂are as above defined and t=0 or 1, at a temperature between about -10°C. to about 100° C. in the presence of a conventional aprotic solvent,in the further presence or absence of a catalytic amount of urethanecatalyst.

Materials comprising polymers of the formulas Ib and Id are formed bypartial (or incomplete) capping in a reaction step. These materials areuseful where post-polymerization modifications are performed such astinting with reactive dyes.

Suitable aprotic solvents for conducting the reactions includeformamide, N,N-dimethylformamide, phosphoric acid tri-dimethylamide,N-methyl-2-pyrrolidone, N,N-dimethylacetamide, acetamide, acetonitrile,acetone, tert-butyl acetate and preferably isopropyl acetate.

Suitable urethane catalysts include tertiary amines such astrimethylamine, triethylamine, N,N-dimethylbenzylamine, or anorgano-metallic urethane catalyst, such as stannous octoate ordibutyltin dilaurate, or sodium acetate.

Alternatively the difunctional reactive agent can be an activatedcarboxy, such as anhydride, an acid halide, a carboxy ester or oxirane,or is a leaving group, such as halide, sulfato or the like. It is clearthat reactants in the various steps of the synthesis be coreactive, e.g.if the perfluoropolyalkylether is terminated with an amine group, thereactive agent can contain an isocyanate, ester, acid halide, halide andthe like. These coupling reactions are well known in the art.

The perfluoropolyalkylether starting materials are known and some arecommercially available. They are described in U.S. Pat. Nos. 3,810,874,3,810,875, 3,847,978, 4,085,137, 4,094,911, 4,089,319 and 4,440,918 andEuropean Patent Applications Nos. EP0084406 and EP0211237 and JapanesePatent Applications cited in the Background of the invention.Perfluoropolyalkylether dimethanols can be prepared by photooxidation oftetrafluoroethylene followed by cleavage and reduction reactions. Someof these are available from Ausimont, U.S.A. and are known as FomblinZDOL derivatives such as Fomblin ZDOL 2000, Fomblin ZDEAL 2000 andFomblin Z-DISOC with the respectives formulas being Z--CH₂ OH)₂,Z--COOCH₃)₂, Z--CONH--C₆ H₃ (CH₃)NCO)]₂ where Z=CF₂ O(C₂ F₄ O)_(r)--(CF₂ O)_(s) --CF₂ (r/s˜0.7). One can also chain extend thesematerials, for example the diols with diisocyanates, before use.

Difunctional (or multifunctional) reactive materials such asdiisocyanate, diester, diepoxides and so on are known and many arecommercially available.

The polyalkylether starting materials are also well known and many arecommercially available (e.g. from Aldrich, Olin and, Polysciences).Hydroxy terminated polyethylene glycols, average molecular weights200-10,000 are available from Aldrich Chemical Company, Inc. U.S.A.Amine-terminated polyethylene glycols are known and some arecommercially available, for example, Jeffamine D-400 (Jefferson Chemicaland Texaco).

It is also possible to use polyalkylether copolymers such asethylene/propylene oxide polymeric diols where the more hydrophilicethylene oxide is in major proportion. Many polymeric copolymeric diolsare known and are described in U.S. Pat. No. 4,780,488. These copolymersinclude poloxamers which are sold under the trade name Pluronic (BASFWyandotte). One can also chain-extend the diols with, for example,diisocyanates before use.

In the third step of the reaction, the reactive vinylic group isintroduced. Isocyanate terminated vinylic monomers are known and someare described in U.S. Pat. No. 4,665,123. Some are commerciallyavailable such as isocyanatoethyl methacrylate (Dow Corning, U.S.A.) andm-isopropenyl-2,2-dimethylbenzyl-isocyanate (m-TMI, Cyanamid). Epoxyterminated vinylic monomers, e.g. glycidyl methacrylate, are known andare commercially available.

It is useful to add minor amounts i.e. up to about 10% of vinyliccomonomer to the composition, for example, to enhance tintability of thematerials. These vinylic comonomers contain reactive groups such ashydroxyl, amine, oxirane and so forth. It is also useful to fine tune aparticular physical property such as modulus, elongation, tensilestrength, hydrophilicity or oxygen permeability by adding minor amountsof additional comonomers.

The vinylic comonomer may be hydrophilic, hydrophobic or may be amixture of hydrophilic and hydrophobic vinylic monomers. Suitablevinylic monomers include those conventional vinylic monomers generallyemployed in the fabrication of soft and hard contact lenses. By ahydrophilic vinylic monomer is meant a monomer which, when polymerizedby conventional free radical polymerization, characteristically yields apolymer which either dissolves in water or is capable of absorbing atleast 10% by weight water under ambient equilibrium conditions.Similarly, suitable hydrophobic vinylic monomers are those monomerswhich, when polymerized by conventional free radical polymerization,characteristically yield a polymer which neither dissolves in water, noris capable of absorbing at least 10% by weight water under ambient (i.e.20° C.) equilibrium conditions.

The vinylic comonomers are reacted with derivatives of formula Iadvantageously in the presence of an inert diluent or solvent, such as asuitable organic solvent, including a lower alkanol, e.g. ethanol,methanol or the like, or an aprotic solvent such asN,N-dimethylformamide, acetamide, acetonitrile, N,N-dimethylacetamide,dimethyl sulfoxide, acetone, tert-butyl acetate, isopropyl acetate ormixture thereof. Also, aqueous/organic solvent systems may be employed.

The derivative of formula I in the presence of vinyl comonomer(s) arepolymerized in the presence of actinic radiation or in the presence of aconventional free radical initiator, such as a peroxide, e.g.di-tert-butyl peroxide, benzoyl peroxide, lauryl peroxide, decanoylperoxide, acetyl peroxide, succinic acid peroxide, methyl ethyl ketoneperoxide, 2,4-dichlorobenzoyl peroxide, isopropyl peroctoate, tert-butylhydroperoxide, tert-butyl perpivalate, tert-butyl peroctoate,diisopropyl peroxydicarbonate, cumene hydroperoxide, tert-butylperbenzoate, tert-butyl peroxymaleic acid, tert-butyl peroxyacetate, andpotassium persulfate, an azo compound, e.g.2,2-azo-bis-isobutyronitrile, 2,2'-azo-bis-(2,4-dimethylvaleronitrile),1,1'-azo-bis-(cyclohexane carbonitrile),2,2'-azo-bis--2,4-dimethyl-4-methoxyvaleronitrile) andphenyl-azo-isobutyronitrile, a photoinitiator, e.g. benzoin methyl etherand 1-hydroxycyclohexylphenyl ketone or actinic radiation such as UVlight or ionizing rays e.g. gamma rays or x-rays.

The derivative of formula I in the presence of vinyl comonomer(s) isadvantageously polymerized upon placement into a mold. The mold may be aconventional spin-casting mold for preparing contact lenses such asdescribed in U.S. Pat. No. 3,408,429, or in a static mold, e.g. asdescribed in U.S. Pat. No. 4,347,198. Alternately, one may prepare aswollen lens blank, dry the lens blank to form the correspondingxerogel, shape the xerogel into a contact lens precurser by lathingmethods known to the art, and swell the shaped xerogel in aqueous mediumto form the corresponding contact lens, as described in U.S. Pat. No.Re. 27,401.

The solution of derivative of formula I in the presence of vinyliccomonomer(s) is advantageously placed into a mold in shape of a contactlens and polymerized. After polymerization, the crosslinked polymer isequilibrated in aqueous or aqueous saline solution. Optimally this posttreatment further includes a heat treatment of the molded lens shapedpolymer. Such heat treastment is characteristically conducted at atemperature between about 60° to 100° C., e.g. in the presence of anaqueous medium. The treatment can vary greatly, but usually isaccomplished in about 5 to 90 minutes. The purpose of this posttreatment is to dimensionally stabilize the crosslinked contact lensmaterial. Also, the treatment may further serve to sterilize such lensmaterial.

Suitable vinylic comonomers for polymerization with the derivative offormula I include conventional hydrophobic and hydrophilic monomers.Suitable hydrophobic monomers include, without limitation, C₁ to C₁₈alkyl acrylates and methacrylate, C₃ to C₁₈ alkyl acrylamides andmethacrylamides, acrylonitrile, methacrylonitrile, vinyl C₁ to C₁₈alkanoates, C₂ to C₁₈ alkenes, C₂ to C₁₈ haloalkenes, styrene, C₁ to C₆alkyl styrenes, vinyl alkyl ethers wherein the alkyl portion has 1 to 6carbon atoms, C₃ -C₁₂ perfluoroalkyl ethyl thiocarbonylaminoethylacrylates and methacrylates, C₃ -C₁₂ fluoroalkyl acrylates andmethacrylates, acryloxy and methacryloxy-alkyl-siloxanes,N-vinylcarbazole, C₁ -C₁₂ alkyl esters of maleic, fumaric, itaconic, andmesaconic acids and the like. Examples of suitable hydrophobic monomersinclude methyl acrylate, ethyl acrylate, propyl acrylate, isopropylacrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, methylmethacrylate, ethyl methacrylate, propyl methacrylate, vinyl acetate,vinyl propionate, vinyl butyrate, vinyl valerate, styrene, chloroprene,vinyl chloride, vinylidine chloride, acrylonitrile, 1-butene, butadiene,methacrylonitrile, vinyl toluene, vinyl ethyl ether,perfluorohexylethylthiocarbonylaminoethyl methacrylate, isobornylmethacrylate, hexafluorobutyl methacrylate,3-methacryloxypropylpentamethyldisiloxane, and bis(methacryloxypropyl)tetramethyldisiloxane.

Suitable hydrophilic monomers include, without limitation, hydroxysubstituted lower alkyl acrylates and methacrylates, acrylamide,methacrylamide, C₁ -C₂ lower alkyl acrylamide and methacrylamide,ethoxylated acrylates and methacrylates, hydroxy substituted lower alkylacrylamide and methacrylamide, hydroxy substituted lower alkyl vinylethers, sodium ethylene sulfonate, sodium styrenesulfonate,2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrole,N-vinylsuccinimide, N-vinylpyrrolidone, 2- and 4-vinylpyridine, acrylicacid, methacrylic acid, amino (by amino including quaternary ammonium),-monoloweralkylamino- or diloweralkylamino- lower alkyl acrylates ormethacrylates, allyl alcohol, and the like.

Specific hydrophilic monomers include hydroxyethyl methacrylate,hydroxyethyl acrylate, acrylamide, methacrylamide,N,N-dimethylacrylamide, allyl alcohol, vinylpyridine,N-vinylpyrrolidone, glycerol methacrylate, N-(1,1-dimethyl-3-oxobutyl)acrylamide, and the like.

Preferred hydrophobic comonomers are methyl methacrylate and glycidylmethacrylate.

Preferred hydrophilic monomers are 2-hydroxyethyl methacrylate, N-vinylpyrrolidone, and dimethylacrylamide.

Optionally, an additional conventional polyreactive crosslinking agentmay be added, such as, allyl compounds e.g. allyl methacrylate, diallylitaconate, monoallyl itaconate, diallyl maleate, diallyl fumarate,diallyl succinate, diallyl phthalate, triallyl cyanurate, triallylisocyanurate, diethylene glycol bis-allyl carbonate, triallyl phosphate,triallyl trimellitate, allyl ether, N,N-diallylmelamine; vinylcompounds, e.g. divinyl benzene, N,N'-methylene-bis-acrylamide, ethyleneglycol dimethacrylate, neopentylglycol dimethacrylate, tetraethyleneglycol dimethacrylate, hexamethylene-bis-maleimide, divinyl urea,bisphenol A bis methacrylate, divinyl adipate, glycerin trimethacrylate,trimethylolpropane triacrylate, trivinyl trimellitate, 1,5-pentadiene,1,3-bis(4-methacryloxybutyl) tetramethyl disiloxane, divinyl ether anddivinyl sulfone; hydroxyl reactive compounds such as: polyvalentisocyanates e.g. hexamethylene diisocyanate, isophorone diisocyanate,toluene diisocyanate; polyaldehydes e.g. glutaraldehyde and glyoxal;polyacids e.g. glutaric acid and oxalic acid; polyepoxides e.g. butanediepoxide, vinylcyclohexene dioxide and butanediol diglycidyl ether;polyols (acid catalysis) e.g. dimethylol urea and diethylene glycol.Also the dimethacrylate formed by reacting perfluoropolyalkyletherdimethanol or poly(ethylene glycol) with two moles of isocyanatoethylmethacrylate can be used.

When employed, about 0.01 to 10 weight percent of crosslinking agent,based upon the weight of formula I derivative, may be present,preferably about 0.01 to about 5 percent, most preferably about lessthan 2 weight percent.

The resultant contact lenses are optically clear, strong, flexible,highly oxygen permeable and wettable. Further, the instant lenses arecharacterized by their ease of manufacture.

In the following examples, all parts are by weight unless otherwisedescribed.

A description of testing methods used on the polymer films is asfollows: (a) Oxygen permeability (DK) is determined from measurements ona Schema Versatae or Createch polarographic cell. (b) Wettability orlubricity is evaluated by a feel comparison to crosslinked polyHEMA(i.e. polymerized 2-hydroxyethyl methacrylate+1% ethylene glycoldimethacrylate). The surface lubricity of polyHEMA is designated (B);more wettable than polyHEMA is designated (A) and a less wettablesurface than polyHEMA is designated (C). (c) Tensile strength isqualitatively evaluated by pulling on a sheet of the material by handand then comparing the result to a material previously evaluated by amicromechanical tester to be 14 kg/cm². A measurement found to besimilar to this "standard" is designated (2); a higher value isdesignated (1); a lower value is designated (3); while a much lowervalue is designated (4).

EXAMPLE 1

This example illustrates the sequential synthesis of theperfluoropolyether/polyether urethane-linked adduct, Z₁--IPDI-PEG-IEM)₂, where Z₁ is a perfluoropolyether, IPDI is isophoronediisocyanate, PEG is a polyethylene glycol and IEM is isocyanatoethylmethacrylate; and, the solution polymerization of this adduct.

Synthesis of Z₁ --IPDI-PEG)₂ Diadduct

30.06 g (0.0136 mole) Fomblin ZDOL 2000 (MW 2200; Montedison, Ausimont)is combined with 6.07 g (0.02734 mole) IPDI and 10 μL dibutyltindilaurate, mixed well and stirred overnight at room temperature formingZ₁ --IPDI)₂. The percentage of isocyanate reacted (generally 48-54%) isdetermined by dibutylamine titration and varies with the precise valueof the Z₁ molecular weight actually used. Then, the calculated molaramount of PEG is added to a solution (solvent, 30-70%) of Z₁ --IPDI)₂ toform Z₁ --IPDI-PEG)₂. Then a urethane catalyst, i.e. dibutyltindilaurate (0.66 mL per gram of solute) is added and the solution allowedto react at 50° C. with stirring overnight (complete disappearance ofisocyanate IR absorption at 2270 cm⁻¹).

Synthesis of Z₁ --IPDI-PEG-IEM)₂ Diadduct

The calculated molar amount of IEM is added, with rapid stirring, to asolution of Z₁ --IPDI-PEG)₂ and reacted at 40°-50° C. (see Example 2samples 1-3) or at room temperature (see Example 2 sample 5 and 6).

Polymerization of Diadduct: Hydrogel Formation

The Z₁ --IPDI-PEG-IEM)₂ adduct in solvent is mixed with initiator(benzoin methyl ether, BME), poured into flat "sandwich" molds andpolymerized with UV light (Sylvania, Blacklight Blue, 15 W) at roomtemperature for 3 hours. The polymerized films are removed from themolds, extracted in water several times, heated in boiling water for 10minutes and then allowed to equilibrate in room temperature water(generally overnight).

EXAMPLE 2

This example shows the resultant water content and oxygen permeabilityvalues of perfluoropolyalkylether/PEG hydrogels, i.e. crosslinked Z₁--IPDI-PEG-IEM)₂, solution polymerized using different molecular weightsof PEG (400, 600) in various amounts of solvent (acetone).

    __________________________________________________________________________    Wt. % In the Polymerization Mixture                                                                     Wt. %                                                                             % H.sub.2 O                                                                        DK                                         Sample                                                                            Z.sub.1                                                                          IPDI                                                                              PEG                                                                              (MW)                                                                              IEM                                                                              Acetone                                                                            BME Content                                                                            (barrer)                                   __________________________________________________________________________    1   39.2                                                                             7.9 14.3                                                                             (400)                                                                             5.5                                                                              33.0 0.1 14.5 67.0                                       2   20.3                                                                             4.1  7.4                                                                             (400)                                                                             2.9                                                                              65.3 0.2 28.9 68.4                                       3   34.7                                                                             7.1 19.0                                                                             (600)                                                                             4.9                                                                              34.3  0.04                                                                             29.2 46.2                                       4   31.6                                                                             6.4 17.4                                                                             ↓                                                                          4.5                                                                              40.1 0.3 37.3 51.6                                       5   26.0                                                                             5.3 14.3                                                                             ↓                                                                          3.7                                                                              50.8 0.3 36.9 53.0                                       6   16.1                                                                             3.3  8.9                                                                             ↓                                                                          2.3                                                                              69.5 0.4 49.2 51.5                                       __________________________________________________________________________

As shown above, water content increases with higher molecular weight PEGand reaction solvent content. The oxygen permeability, however,decreases with the higher molecular weight PEG.

EXAMPLE 3

This example illustrates a range of Z₁ /PEG hydrogel water contentsobtained by varying the molecular weight of the PEG and the proportionof solvent IPAC (isopropyl acetate). Films are made as in Example 1except that the molecular weight of the PEG is 600, 900, 1000 or 1500and the solvent used is isopropyl acetate. IEM is reacted at 40°-50° C.for all samples.

    __________________________________________________________________________    Wt. % In the Polymerization Mixture                                                                      Wt. %                                                                             % H.sub.2 O                                    Sample                                                                             Z.sub.1                                                                          IPDI                                                                              PEG                                                                              (MW) IEM                                                                              IPAC                                                                              BME Content                                        __________________________________________________________________________    1    35.3                                                                             7.2 19.3                                                                             (600)                                                                              5.0                                                                              33.2                                                                              0.06                                                                              21.9                                           2    27.1                                                                             5.5 14.8                                                                             ↓                                                                           3.8                                                                              48.8                                                                              0.06                                                                              31.2                                           3    20.8                                                                             4.2 11.3                                                                             ↓                                                                           2.9                                                                              60.8                                                                              0.04                                                                              45.8                                           4    29.4                                                                             5.9 24.0                                                                             (900)                                                                              4.1                                                                              36.6                                                                              0.05                                                                              39.5                                           5    25.2                                                                             5.1 20.6                                                                             ↓                                                                           3.6                                                                              45.7                                                                              0.04                                                                              40.7                                           6    20.9                                                                             4.2 17.1                                                                             ↓                                                                           3.0                                                                              54.8                                                                              0.05                                                                              42.8                                           7    27.3                                                                             5.5 24.9                                                                             (1000)                                                                             3.9                                                                              38.4                                                                              0.05                                                                              42.9                                           8    23.8                                                                             4.8 21.7                                                                             ↓                                                                           3.4                                                                              46.3                                                                              0.05                                                                              45.1                                           9    22.0                                                                             4.4 20.0                                                                             ↓                                                                           3.3                                                                              47.7                                                                              0.05                                                                              45.0                                           10   20.2                                                                             4.1 18.3                                                                             ↓                                                                           2.8                                                                              54.6                                                                              0.03                                                                              48.1                                           11   15.9                                                                             3.2 14.5                                                                             ↓                                                                           2.2                                                                              64.2                                                                              0.05                                                                              54.2                                           12   13.9                                                                             2.8 12.6                                                                             ↓                                                                           2.0                                                                              68.7                                                                              0.04                                                                              52.9                                           13   18.9                                                                             3.9 25.9                                                                             (1500)                                                                             2.7                                                                              48.6                                                                              0.05                                                                              57.9                                           14   16.5                                                                             3.4 22.6                                                                             ↓                                                                           2.3                                                                              55.2                                                                              0.06                                                                              61.1                                           15   14.7                                                                             3.1 20.1                                                                             ↓                                                                           2.1                                                                              60.1                                                                              0.07                                                                              61.5                                           __________________________________________________________________________

As shown above water content increases with increasing molecular weightPEG and solvent content.

EXAMPLE 4

This example shows the effect of hydrophilic comonomer addition on thephysical properties of Z₁ /PEG hydrogel films. Films are made as inExample 3 except that comonomer N,N-dimethylacrylamide, DMA;N-vinylpyrrolidone, NVP; or 2-hydroxyethyl methacrylate, (HEMA) is addedjust prior to the addition of initiator.

    __________________________________________________________________________                                         Physical Properties of Hydrogel          Wt. % In the Polymerization Mixture                                                                            %   % H.sub.2 O                              Sample                                                                            Z.sub.1                                                                          IPDI                                                                              PEG                                                                              (MW)                                                                              IEM                                                                              Comonomer                                                                             IPAC                                                                              BME Content                                                                            Clarity                                                                            Wettability                                                                         Strength                 __________________________________________________________________________     1  24.4                                                                             4.9 19.9                                                                              (900)                                                                            3.4                                                                              17.1                                                                             DMA  30.3                                                                              0.05                                                                              54.4 Clear                                                                              A     3                         2  24.5                                                                             4.9 20.0                                                                             ↓                                                                          3.5                                                                              16.7                                                                             NVP  30.4                                                                              0.05                                                                              48.8 ↓                                                                           ↓                                                                            3                         3  24.5                                                                             4.9 20.0                                                                             ↓                                                                          3.5                                                                              16.6                                                                             HEMA 30.5                                                                              0.05                                                                              37.1 ↓                                                                           ↓                                                                            2                         4  29.4                                                                             5.9 24.0                                                                             ↓                                                                          4.1                                                                              --      36.6                                                                              0.05                                                                              39.5 ↓                                                                           ↓                                                                            2                         5  24.8                                                                             5.0 22.6                                                                             (1000)                                                                            3.5                                                                              9.1                                                                              DMA  35.0                                                                              0.05                                                                              52.6 ↓                                                                           ↓                                                                            3                         6  22.8                                                                             4.6 20.7                                                                             ↓                                                                          3.2                                                                              16.6    32.1                                                                              0.05                                                                              57.1 ↓                                                                           ↓                                                                            ↓                  7  21.0                                                                             4.3 19.1                                                                             ↓                                                                          3.0                                                                              9.5     43.1                                                                              0.06                                                                              54.4 ↓                                                                           ↓                                                                            ↓                  8  19.2                                                                             3.9 17.5                                                                             ↓                                                                          2.7                                                                              17.4    39.4                                                                              0.05                                                                              60.1 ↓                                                                           ↓                                                                            3-4                       9  24.8                                                                             5.0 22.6                                                                             ↓                                                                          3.5                                                                              9.2                                                                              NVP  34.9                                                                              0.05                                                                              48.6 ↓                                                                           ↓                                                                            3                        10  22.7                                                                             4.6 20.7                                                                             ↓                                                                          3.2                                                                              16.8    32.0                                                                              0.05                                                                              54.7 Hazy ↓                                                                            4                        11  21.1                                                                             4.3 19.2                                                                             ↓                                                                          3.0                                                                              9.0     43.4                                                                              0.04                                                                              49.7 Clear                                                                              ↓                                                                            3                        12  19.2                                                                             3.9 17.4                                                                             ↓                                                                          2.7                                                                              17.5    39.3                                                                              0.05                                                                              52.3 ↓                                                                           ↓                                                                            4                        13  24.8                                                                             5.0 22.6                                                                             ↓                                                                          3.5                                                                              9.1                                                                              HEMA 35.0                                                                              0.05                                                                              42.7 ↓                                                                           ↓                                                                            3                        14  22.8                                                                             4.6 20.7                                                                             ↓                                                                          3.2                                                                              16.6    32.1                                                                              0.05                                                                              40.0 ↓                                                                           ↓                                                                            ↓                 15  21.0                                                                             4.2 19.0                                                                             ↓                                                                          3.0                                                                              9.8     43.0                                                                              0.05                                                                              44.9 Sl. Hazy                                                                           ↓                                                                            ↓                 16  19.2                                                                             3.9 17.5                                                                             ↓                                                                          2.7                                                                              17.4    39.4                                                                              0.05                                                                              44.8 Sl. Hazy                                                                           ↓                                                                            ↓                 17  27.3                                                                             5.5 24.9                                                                             ↓                                                                          3.9                                                                              --      38.4                                                                              0.05                                                                              42.9 Clear                                                                              ↓                                                                            ↓                 18  15.7                                                                             3.3 21.5                                                                             (1500)                                                                            2.2                                                                              16.8                                                                             DMA  40.5                                                                              0.05                                                                              69.6 ↓                                                                           ↓                                                                            2                        19  15.7                                                                             3.3 21.5                                                                             ↓                                                                          2.2                                                                              16.8                                                                             NVP  40.5                                                                              0.05                                                                              63.2 ↓                                                                           ↓                                                                            3-4                      20  15.4                                                                             3.2 21.5                                                                             ↓                                                                          2.2                                                                              18.9                                                                             HEMA 39.8                                                                              0.06                                                                              55.8 Hazy ↓                                                                            2                        21  18.9                                                                             3.9 25.9                                                                             ↓                                                                          2.7                                                                              --      48.6                                                                              0.05                                                                              57.9 Clear                                                                              ↓                                                                            3                        __________________________________________________________________________     DMA = dimethylacrylamide;                                                     NVP = Nvinylpyrrolidone;                                                      HEMA = 2hydroxyethyl methacrylate                                        

As shown above, addition of hydrophilic comonomers has little effect onwettability or tensile strength.

EXAMPLE 5

This example compares the effect of initiator level on the physicalproperties of similar composition Z₁ /PEG hydrogel films. The films areprepared in a similar manner to that in Example 1.

In general, 3.00 g (0.0016 mole) Fomblin ZDOL 2000, MW 1851 (previouslybubbled with nitrogen for 2 hours while stored over molecular sieves) iscombined with 0.72 g (0.0032 mole) IPDI and 2.5 μL dibutyltin dilaurate(DBTL) catalyst under nitrogen, mixed well and stirred overnight at roomtemperature. The percentage of isocyanate reacted is determined bytitration to be 48-53%. PEG 1000 is reacted with Z₁ --IPDI)₂ in thepresence of solvent (approximately 38% by weight isopropyl acetate,IPAC). Then 0.66 μL DBTL is added per gram solute and the solutionreacted at 50° C. with stirring overnight under nitrogen. The solutionis cooled to room temperature and initiator (BME) added. The solution iscentrifuged five minutes (Eppendorf 5412) poured into "sandwich" moldsand UV irradiated at room temperature for three hours. After waterextraction, strength and wettability testing is performed.

    __________________________________________________________________________                               Physical Properties of Hydrogel                    Wt. % In the Polymerization Mixture                                                                      % H.sub.2 O                                        Sample                                                                            Z.sub.1                                                                           IPDI                                                                              PEG                                                                              IEM                                                                              IPAC                                                                              % BME                                                                              Content                                                                            Clarity                                                                            Wettability                                                                         Strength                           __________________________________________________________________________    1   24.8                                                                              5.9 26.8                                                                             4.2                                                                              38.4                                                                               0.05                                                                              36.7 Clear                                                                              B     2                                  2   24.6                                                                              5.9 26.7                                                                             4.2                                                                              38.7                                                                               0.05                                                                              47.9 ↓                                                                           A     4                                  3   25.9                                                                              5.8 25.9                                                                             4.0                                                                              38.4                                                                              0.1  46.3 ↓                                                                           B     2                                  4   24.8                                                                              6.0 26.8                                                                             4.1                                                                              38.3                                                                              0.1  47.5 ↓                                                                           A     3                                  5   24.7                                                                              6.0 26.8                                                                             4.2                                                                              38.4                                                                              0.1  50.4 ↓                                                                           A     3                                  6   25.9                                                                              5.8 25.9                                                                             4.0                                                                              38.4                                                                              0.2  48.4 ↓                                                                           B     2                                  7   24.8                                                                              6.0 26.8                                                                             4.1                                                                              36.3                                                                              0.2  51.3 ↓                                                                           A     3                                  8   25.9                                                                              5.8 25.9                                                                             4.0                                                                              38.4                                                                              0.5  48.8 ↓                                                                           A     2                                  __________________________________________________________________________

As shown above, increasing initiator level from 0.05 to 0.1% and higherappears to improve property reproducibility especially water content andstrength; but no added strength is found by further increasing initiatorlevel to 0.5%.

EXAMPLE 6

This example illustrates the effect of various crosslinking agents onthe physical properties of perfluoropolyether/PEG hydrogel films. Thecrosslinkers used are: a dimethacrylate of PEG 600, a dimethacrylate ofZDOL 1000 and ethylene glycol dimethacrylate.

The dimethacrylate of PEG 600 is synthesized by combining 2.425 g (0.004mole) PEG 600 with 1.2578 g (0.008 mole) IEM, mixing well and adding 2μL DBTL and stirring overnight at room temperature. Reaction completionis indicated by disappearance of isocyanate IR absorption at 2270 cm⁻¹.

The dimethacrylate of ZDOL 1000, Z₁ --IEM)₂, is synthesized by combining1.1115 g (0.00085 mole) Fomblin ZDOL 1000 (MW 1301) with 0.2652 g(0.0017 mole) IEM, mixing well and then adding 2 μL DBTL and stirringfor three hours at room temperature. Disappearance of the isocyanate IRabsorption is used to monitor reaction completion. Ethylene glycoldimethacrylate (EGDMA) is distilled from a commercial source (Sartomer)before use.

    __________________________________________________________________________    Wt. % In the Polymerization Mixture   Physical Properties of Hydrogel                    PEG                        % H.sub.2 O                                                                            Wetta-                         Sample                                                                            Z.sub.1                                                                          IPDI                                                                              1000                                                                             IEM                                                                              IPAC                                                                              Comonomer   % BME                                                                              Content                                                                            Clarity                                                                           bility                                                                            Strength                   __________________________________________________________________________    1   22.4                                                                             5.4 24.3                                                                             3.8                                                                              34.8                                                                               9.3 PEG 600-(IEM).sub.2                                                                  0.1  49.8 Clear                                                                             A   3                          2   19.9                                                                             4.8 22.4                                                                             3.5                                                                              36.2                                                                              13.1 PEG 600-(IEM).sub.2                                                                  0.1  48.3 ↓                                                                          A   4                          3   20.7                                                                             4.9 22.3                                                                             3.5                                                                              35.4                                                                              13.2 PEG 600-(IEM).sub.2                                                                   0.09                                                                              48.6 ↓                                                                          A   4                          4   24.4                                                                             5.9 26.4                                                                             4.1                                                                              38.1                                                                               1.1 EGDMA  0.1  45.3 ↓                                                                          B   3                          5   24.5                                                                             5.9 26.4                                                                             4.1                                                                              38.1                                                                               1.0 ZDOL 1000(IEM).sub.2                                                                 0.1  53.6 ↓                                                                          A   2-3                        6   24.7                                                                             5.9 26.7                                                                             4.2                                                                              38.5                                                                                    ↓                                                                            0.1  46.7 ↓                                                                          A   3                          __________________________________________________________________________     PEG 600(IEM).sub.2 = PEG 600 dimethacrylate;                                  EGDMA = ethylene glycol dimethacrylate;                                       ZDOL 1000(IEM).sub.2 = ZDOL 1000 dimethacrylate                          

EXAMPLE 7

This example shows the physical properties of perfluoropolyether/PEGhydrogel films made by combining the diadducts of Z₁ --IPDI-PEG-IEM)₂which have different PEGs, but the same Z₁ (i.e. ZDOL 2000). The PEGsused are 400, 600 and 1000. The reaction solutions are prepared inisopropyl acetate as in Example 5 except that nitrogen degassing is notused. The solutions are mixed in various ratios just prior to initiator(BME) addition.

    __________________________________________________________________________                                               Physical Properties of                                                        Hydrogel                           Mole Ratio      Wt. % In the Polymerization Mixtures                                                                     % H.sub.2 O                                                                              Wetta-                  Sample                                                                            Z.sub.1 -(IPDI-PEG-IEM).sub.2                                                             Z.sub.1                                                                          IPDI                                                                              PEG (MW)                                                                              IEM                                                                              IPAC                                                                              % BME                                                                              Content                                                                            Clarity                                                                             bility                                                                            Strength            __________________________________________________________________________    1   1 PEG 1000/1 PEG 600                                                                      27.1                                                                             6.5 14.8                                                                              (1000)                                                                            4.6                                                                              38.3                                                                              0.05 39.0 Clear A   3                                           8.7                                                                               (600)               ↓                                                                            ↓                                                                          ↓            2   3 PEG 1000/1 PEG 600                                                                      25.9                                                                             6.2 21.1                                                                              (1000)                                                                            4.3                                                                              38.4                                                                              0.06 42.4 ↓                                                                            ↓                                                                          ↓                                    4.1                                                                               (600)               ↓                                                                            ↓                                                                          ↓            3   1 PEG 1000/1 PEG 400                                                                      28.6                                                                             6.5 15.6                                                                              (1000)                                                                            4.8                                                                              38.3                                                                              0.05 35.0 ↓                                                                            ↓                                                                          ↓                                    6.1                                                                               (400)               ↓                                                                            ↓                                                                          ↓            4   3 PEG 1000/1 PEG 400                                                                      26.5                                                                             6.4 21.2                                                                              (1000)                                                                            4.5                                                                              38.3                                                                              0.05 40.9 ↓                                                                            ↓                                                                          ↓                                    2.9                                                                               (400)               ↓                                                                            ↓                                                                          ↓            5   PEG 1000    24.7                                                                             5.9 26.7                                                                              (1000)                                                                            4.2                                                                              38.5                                                                              0.1  46.7 ↓                                                                            ↓                                                                          ↓            __________________________________________________________________________

The results show that though the water content of a Z₁ --IPDI-PEG1000-IEM)₂ film is lowered slightly by the copolymerization with Z₁--IPDI-PEG 400-IEM)₂ or Z₁ --IPDI-PEG 600-IEM)₂, the clarity,wettability and strength appear the same.

EXAMPLE 8

This example shows the effect of a lower molecular weight (i.e.approximately 1000 as opposed to approximately 2000) perfluoropolyetheron the properties of a Z₁ /PEG hydrogel. The synthesis of these Z₁--IPDI-PEG-IEM)₂ diadducts is similar to that described in Example 3.More specifically, 5.0082 g (0.0038 mole) Fomblin ZDOL 1000 (MW 1301) isreacted with 1.7121 g (0.007 mole) IPDI in solvent (20% isopropylacetate) while stirring at room temperature overnight in the presence of2 μL DBTL; some samples (i.e. sample numbers 3, 5 and 6) are reactedwithout solvent. The Z₁ --IPDI)₂ diadduct is then reacted with 2 molesof PEG (i.e. 200, 400, 600, 900 or 1000). The PEG is first dissolved ina certain quantity of isopropyl acetate (the weight of solventcalculated to be 40% of the final reaction mixture) at 50° C. (PEG 600,900, 1000) or at room temperature (PEG 200, 400).

In Sample 1 for example, 0.2211 g (0.0011 mole) PEG 200 is dissolved in0.5692 g IPAC then 1.2098 g of the Z₁ --IPDI)₂ adduct is added, themixture mixed well followed by the addition of 0.78 μL DBTL and stirringovernight at 50° C. The solution is then cooled to room temperature,0.1714 g (0.0011 mole) IEM added and the mixture reacted with stirringat room temperature overnight. Addition of initiator (BME),polymerization and water equilibration are similar to that described inExample 1.

    __________________________________________________________________________                                 Physical Properties of Hydrogel                             % IPAC In The             Oxygen Permeability                      Sample                                                                            MW PEG Polymerization Mixture                                                                    % BME % H.sub.2 O Content                                                                   (barrer)    Observation                  __________________________________________________________________________    1   200    40          0.48   5.92   25.3        very slightly hazy on                                                         edges;                                                                        wettability = B              2   400                0.49  19.48   24.0        clear; wettability = B       3   600                0.06  34.29   20.8        clear; yellow edges;                                                          wettability = A              4   900                0.51  47.66   25.9        clear; wettability = A       5   1000               0.07  50.28   22.9        clear; wettability = A       6   1000               0.48  51.50   --          clear; wettability =         __________________________________________________________________________                                                     A                        

As shown above, water content and wettability increase with increasingmolecular weight of PEG.

EXAMPLE 9

This example shows the effect of PEG molecular weight and solventcontent (isopropyl acetate) on various physical properties ifperfluoropolyether/polyether hydrogels obtained using Fomblin ZDOL TX2000 (Z₁ TX, MW 2288) a perfluoropolyether with an additional 1 or 2ethylene oxide units adducted to the terminal hydroxyl groups of ZDOL2000.

Films are made in a similar manner to those described in Example 3. Thereaction of Z₁ TX and two moles of IPDI is monitored by isocyanatetitration and the percent isocyanate reacted is found to beapproximately 50% (47-52%). The product, Z₁ TX--IPDI-PEG-IEM)₂ is formedthrough the reaction of two moles of IEM with Z₁ TX--IPDI-PEG)₂ adductin IPAC at room temperature overnight.

As shown in the table below, in general, use of the perfluoropolyetherZ₁ TX yielded strong clear films whose percent water content increaseswith PEG molecular weight and solvent content.

    __________________________________________________________________________              % IPAC In The                                                                             Physical Properties of Hydrogel                         Sample                                                                            MW PEG                                                                              Polymerization Mixture                                                                    % H.sub.2 O Content                                                                   Clarity/Wettability/Strength                    __________________________________________________________________________    1   400   28          16      Clear                                                                              A   2                                      2   ↓                                                                            39          17      Clear                                                                              B   1                                      3   ↓                                                                            48          21      Hazy B   2                                      4   ↓                                                                            66          28      Cloudy                                                                             B   2                                      5   600   38          29      Clear                                                                              A   1                                      6   ↓                                                                            50          30      Sl. hazy                                                                           A   2                                      7   ↓                                                                            59          39      Hazy B   3                                      8   900   29          39      Clear                                                                              A   4                                      9   ↓                                                                            40          40      Clear                                                                              ↓                                                                          1                                      10  ↓                                                                            50          43      Clear                                                                              ↓                                                                          1                                      11  ↓                                                                            58          47      Clear                                                                              ↓                                                                          1                                      12  1000  28          47      Clear                                                                              ↓                                                                          1                                      13  ↓                                                                            38          42      Clear                                                                              ↓                                                                          1                                      14  ↓                                                                            38          40      Clear                                                                              ↓                                                                          2                                      15  ↓                                                                            49          43      Clear                                                                              ↓                                                                          1                                      16  ↓                                                                            59          47      Sl. hazy                                                                           ↓                                                                          4                                      17  1500  39          55      Clear                                                                              ↓                                                                          2                                      18  ↓                                                                            39          56      Clear                                                                              ↓                                                                          2                                      19  ↓                                                                            49          57      Clear                                                                              ↓                                                                          2                                      20  ↓                                                                            59          60      Clear                                                                              ↓                                                                          1                                      __________________________________________________________________________

EXAMPLE 10

This example shows the synthesis of a perfluoropolyether/polyetherhydrogel in which the urethane group linking the perfluoropolyetherchain and polyether chain (reaction with IPDI) is replaced by an etherlinkage; this is accomplished by using an epoxy-terminated PEG.

More specifically, 2.1091 g (0.00096 mole) Fomblin ZDOL 2000 (MW 2200)is reacted at 60° C. overnight with 0.7749 g (0.0096 mole) polyethyleneglycol 400 diglycidyl ether (PEGE 400, Polysciences), using 0.0167 gtriethylamine catalyst. After 16 hours, the temperature of the mixture(opaque) is raised to 70° C., 0.0220 g triethylamine added and themixture stirred overnight leading to a clear, yellow, viscous product,Z₁ --O-PEG 400)₂. Then 0.5213 g (0.00017 mole) of Z₁ --O-PEG 400)₂ iscombined with 1.8890 g dimethyl sulfoxide, DMSO, (Aldrich Gold Label,99.9%) and 0.0539 g (0.00035 mole) IEM which is added dropwise to therapidly stirring mixture. The solution is reacted at room temperatureapproximately 72 hours. Then 0.0040 g BME is added and the solutionpoured into a "sandwich" mold and UV irradiated at room temperature for13 hours resulting in a soft gel. This material after equilibration inwater becomes a clear hydrogel film.

EXAMPLE 11

This example shows the fabrication of prototypeperfluoropolyether/polyether lenses from polypropylene contact lensmolds. The reaction solution is made as in Example 5 (samples 3-5) using0.1% BME as initiator. The solution is pipetted into the lens molds andUV cured for 3 hours. After water extraction and boiling, one obtainsoptically clear, strong lenses. Micromechanical tensile tests performedon the lenses yield the following properties; stress of 3.6 kg/cm²,Young's modulus of 26 kg/cm² and a 13% elongation.

EXAMPLE 12

This example illustrates the preparation of hydrogels obtained viapolymerization of partially IEM capped Z₁ --IPDI-PEG 1000)₂ adduct (Z₁Adduct). The incompletely capped adduct, i.e. mixtures of PEG-IPDI-Z₁--IPDI-PEG-IEM and IEM-PEG-IPDI---Z₁ --IPDI-PEG-IEM, is prepared as inExample 1 except that 50%-90% of the amount of IEM is added to partiallyreact the PEG 1000 hydroxyl groups. The adducts are then polymerizedwith or without comonomer (DMA, HEMA, NVP) into sheets (samples 1-5) orlenses (samples 6-8) using UV irradiation (3 hours, 0.05% BME initiator)and water equilibration.

    __________________________________________________________________________    Polymerization Mixture                                                        Z.sub.1 :IPDI:PEG:IEM                                                                        % Z.sub.1        Physical Properties of Hydrogel               Sample                                                                             Molar Ratio                                                                             Adduct                                                                            % IPAC                                                                             % Comonomers                                                                          % H.sub.2 O Content                                                                   Clarity                                                                           Wettability                       __________________________________________________________________________    1    1:2:2:1   61.9                                                                              38.1 --      54.7    Clear                                                                             A                                 2    ↓  54.6                                                                              45.4 --      64.1    Clear                                                                             A                                 3    ↓  49.6                                                                              41.2 9.2 DMA 68.7    Clear                                                                             A                                 4    ↓  49.6                                                                              41.2 .sup. 9.2 HEMA                                                                        55.7    Hazy                                                                              A                                 5    ↓  49.7                                                                              41.2 9.1 NVP.sup.                                                                          58.3    Clear                                                                             A                                 6    1:2:2:1.5 66.3                                                                              33.7 --      52.9    Clear                                                                             A                                 7    1:2:2:1.8 61.1                                                                              38.9 --      52.7    Clear                                                                             A                                 8    1:2:2:2   61.6                                                                              38.4 --      48.7    Clear                                                                             A                                 (Control)                                                                     __________________________________________________________________________

EXAMPLE 13

This example illustrates the preparation and physical properties of thehydrogels obtained when various amounts of the Z₁ --IPDI-PEG-IEM)₂diadduct (Z₁ Diadduct) are copolymerized with the reaction product (RPAdduct) of Z₁ --IPDI-PEG)₂ and an equal molar amount of IEM. The Z₁--IPDI-PEG-IEM)₂ diadduct is prepared as in Example 1 using 37.4% IPACas solvent. The RP Adduct is also prepared as in Example 1 with 38.1%IPAC except that 50% of the amount of IEM is added. These materials,i.e. Z₁ Diadduct and RP Adduct in IPAC are combined in various ratiosand UV polymerized (3 hours, 0.05% BME initiator) into sheets.

    __________________________________________________________________________    Polymerization Mixture                                                        % RP      % Z.sub.1                                                                           Physical Properties of Hydrogel                               Sample                                                                            Adduct                                                                              Diadduct                                                                            % H.sub.2 O Content                                                                   Clarity                                                                           Wettability                                                                         Strength                                    __________________________________________________________________________    1   85.4  14.6  53.01   Clear                                                                             A     3-4                                         2   84.6  15.4  52.08   ↓                                                                          A     4                                           3   50.0  50.0  44.39   ↓                                                                          A     3                                           4   50.0  50.0  48.01   ↓                                                                          A     3                                           5   14.8  85.2  44.16   ↓                                                                          A     3                                           6   100.0 --    54.71   ↓                                                                          A     4                                           7   --    100.0 44.45   ↓                                                                          A     3                                           __________________________________________________________________________

As shown above, water content tends to increase with increasing RPAdduct content.

EXAMPLE 14

This example illustrates the tensile strength of lenses polymerized fromthe Z₁ --IPDI-PEG 1000-IEM)₂ diadduct (Z₁ Diadduct) with or withoutadditional comonomer adducts. The Z₁ --IPDI-PEG 1000-IEM)₂ diadduct isprepared as in Example 1. The comonomers used are prepared by reactionof 1 mole Z₁ with one mole IEM (Z₁ /IEM) or two moles IEM (Z₁ --IEM)₂)using dibutyltin dilaurate as catalyst. The diadduct in IPAC is combinedwith the additional comonomer adduct(s) and polymerized using UVirradiation (3 hours, 0.1% BME initiator).

    __________________________________________________________________________    Polymerization Mixture         Physical Properties of Hydrogel                     % Z.sub.1                                                                          % Comonomer          Young's Modulus                                                                        Stress                                Sample                                                                             Diadduct                                                                           Adduct  % IPAC                                                                             % H.sub.2 O Content                                                                   (kg/cm.sup.2)                                                                          (kg/cm.sup.2)                                                                      % Elongation                     __________________________________________________________________________    1    61.0 1.0 Z.sub.1 -(IEM).sub.2                                                              38.0 47.6    21 ± 4                                                                              3.0 ± 0.9                                                                       14 ± 3                        2    57.6 1.1 Z.sub.1 -(IEM).sub.2                                                              35.8 44.3    22 ± 5                                                                              2.9 ± 0.4                                                                       13 ± 3                                  5.5 Z.sub.1 /IEM                                                    3    61.6 --      38.4 48.7    25 ± 5                                                                              4.0 ± 0.7                                                                       15 ± 2                        Control                                                                       __________________________________________________________________________

What is claimed is:
 1. A method of preparing a hydrogel ophthalmicdevice or contact lens by the crosslinking of (a) a macromer containingperfluoropolyalkylether and polyalkylether segments and ethylenicallyunsaturated moieties, having the formula I, more specifically as seen informulas Ia to Id,

    E--T--L--Q--X--Z--X--Q--L--T--E,                           (Ia)

    E--T--L--Q--X--Z--X--Q--L,                                 (Ib)

    E--T--L--Q--X--G--X--Q--L--T--E, or                        (Ic)

    E--T--L--Q--X--G--X--Q--L                                  (Id)

wherein Z is --(C_(a) F_(2a) O)_(b) --CF₂ --, where a is 1 to 4, b is 2to 200; X is a direct bond, --CH₂ --, --CH₂ OCH₂ CHOHCH₂ --, --CH₂ (OCH₂CH₂)_(y) -- or carbonyl where y is 1 to 10 and where in each case thecarbon atom is attached to Z or G; Q is a direct bond or--ACONH--R--NHCO-- where A is oxa or imino and R is a divalent aliphaticgroup having from 2 to 14 carbon atoms, a divalent 5- or 6-memberedcycloaliphatic group having 5 to 14 carbon atoms or an arylene grouphaving 6 to 14 carbon atoms; L is --A(C_(m) H_(2m) O)_(n) C_(m) H_(2m)AY-- or L₁ where Y is a direct bond or H and m is 2 to 4 or mixturesthereof and n is 5 to 100, where A is attached to Q; T is --CONH--R₅ A--or --CONH--R--NHCOOR₅ A-- or --CONH--R--NHCO--A-- or --R₅ A-- or directbond where the carbonyl group is attached to L, where R₅ is alkylene orhydroxy-substituted alkylene of 2 to 15 carbon atoms and R is as above;##STR7## where R₁ is hydrogen or methyl, and R₂ is hydrogen, methyl or--COOR₃ where R₃ is hydrogen or alkyl of 1 to 4 carbon atoms with theproviso that,when R₁ is methyl, R₂ is hydrogen, R₄ is hydrogen or methyland G is --(C_(a) F_(2a) O)_(b) --CF₂ [CH₂ --OCONH--R--NHCOOCH₂ CF₂(OC_(a) F_(2a))_(b) ]_(x) or --(C_(a) F2aO)_(b) --CF₂ [CH₂--NHCONH--R--NHCONHCH₂ CF₂ (OC_(a) F_(2a))_(b) ]_(x) where x is 1 to 3;

    L.sub.1 is --A(C.sub.m H.sub.2m O).sub.n [C.sub.m H.sub.2m ACONH--R--NHCOA(C.sub.m H.sub.2m O).sub.n.sbsb.1 ].sub.z C.sub.m H.sub.2m AY

where n₁ is 5 to 100, z is 1 to 10 and Y is a direct bond or H; with (b)a vinylic comonomer selected from (i) hydrophilic monomers selected fromhydroxy-substituted lower alkyl acrylates and methacrylates, acrylamide,methacrylamide, C₁ -C₂ lower alkyl acrylamide and methacrylamide,ethoxylated acrylates and methacrylates, hydroxy substituted lower alkylacrylamide and methacrylamide, hydroxy substituted lower alkyl vinylethers, sodium ethylene sulfonate, sodium styrenesulfonate,2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrole,N-vinylsuccinimide, N-vinylpyrrolidone, 2- and 4-vinylpyridine, acrylicacid, methacrylic acid, amino (by amino including quaternary ammonium),-monoloweralkylamino- or diloweralkylamino- lower alkyl acrylates ormethacrylates and allyl alcohol; (ii) hydrophobic monomers selected fromC₁ to C₁₈ alkyl acrylates and methacrylate, C₃ to C₁₈ alkyl acrylamidesand methacrylamides, acrylonitrile, methacrylonitrile, vinyl C₁ to C₁₈alkanoates, C₂ to C₁₈ alkenes, C₂ to C₁₈ haloalkenes, styrene, C₁ to C₆alkyl styrenes, vinyl alkyl ethers wherein the alkyl portion has 1 to 6carbon atoms, C₃ -C₁₂ perfluoroalkyl ethyl thiocarbonylaminoethylacrylates and methacrylates, C₃ -C₁₂ fluoroalkyl acrylates andmethacrylates, acryloxy and methacryloxy-alkyl-siloxanes,N-vinylcarbazole, C₁ -C₁₂ alkyl esters of maleic, fumaric, itaconic, andmesaconic acids;(iii) polyreactive crosslinking agents such as allylmethacrylate, diallyl itaconate, monoallyl itaconate, diallyl maleate,diallyl fumarate, diallyl succinate, diallyl phthalate, triallylcyanurate, triallyl isocyanurate, diethylene glycol bis-allyl carbonate,triallyl phosphate, triallyl trimellitate, allyl ether,N,N-diallylmelamine; vinyl compounds, e.g. divinyl benzene,N,N'-methylene-bis-acrylamide, ethylene glycol dimethacrylate,neopentylglycol dimethacrylate, tetraethylene glycol dimethacrylate,hexamethylene-bis-maleimide, divinyl urea, bisphenol A bis methacrylate,divinyl adipate, glycerin trimethacrylate, trimethylolpropanetriacrylate, trivinyl trimellitate, 1,5-pentadiene,1,3-bis(4-methacryloxybutyl) tetramethyl disiloxane, divinyl ether, anddivinyl sulfone; and the dimethacrylate formed by reactingperfluoropolyalkylether dimethanol or poly(ethylene glycol) with twomoles of isocyanatoethyl methacrylate;and (iv) mixtures of (i), (ii) and(iii); in an inert solvent in a mold by free radical polymerization andequilibrating the resulting solvent swollen crosslinked ophthalmicdevice or contact lens in an aqueous medium.
 2. A method according toclaim 1 wherein the solvent is a lower alkanol, N,N-dimethylformamide,acetamide, acetonitrile, N,N-dimethylacetamide, dimethyl sulfoxide,acetone, tert-butyl acetate, isopropyl acetate or mixtures thereof.
 3. Amethod according to claim 2 wherein the solvent is isopropyl acetate. 4.An ophthalmic device made according to claim
 1. 5. A hydrogel contactlens made according to claim
 1. 6. A hydrogel contact lens madeaccording to claim 1 with greater than 20% water content.
 7. A hydrogelcontact lens made according to claim 1 with greater than 30% watercontent.
 8. A hydrogel contact lens made according to claim 1 withgreater than 40% water content.
 9. A hydrogel contact lens madeaccording to claim 1 with greater than 50% water content.
 10. A hydrogelcontact lens made according to claim 1 with between 25 and 55% watercontent.
 11. An ophthalmic device prepared by the process of claim 1.12. An ophthalmic device prepared by the process of claim 1 wherein themacromer (a) has the formula (Ia) E--T--L--Q--X--Z--X--Q--L--T--E. 13.An ophthalmic device prepared by the process of claim 1 where in themacromer (a), E is --CO--C(CH₃)=CH₂, T is --CONH--CH₂ CH₂ --O--, L is--O(C₂ H₄ O)_(n) C₂ H₄ O-- where n is 19--25, Q is--OCONH--isophorone--NHCO--, X is --CH₂ --, and Z is --CF₂ O(C₂ F₄O)_(r) --(CF₂ O)_(s) --CF₂ -- where r/s is about 0.7.
 14. An ophthalmicdevice prepared by the process of claims 1 where the vinylic comonomer(b) is up to 10% by weight.
 15. An ophthalmic device prepared by theprocess of claim 1 wherein the vinylic comonomer (b) is 2-hydroxyethylmethacrylate, N-vinylpyrrolidone, N,N-dimethylacrylamide, ethyleneglycol dimethacrylate, the reaction product of poly(ethylene glycol)with two moles of 2-isocyanatoethyl methacrylate or the reaction productof perfluoropolyalkylether dimethanol with two moles of2-isocyanatoethyl methacrylate.
 16. A contact lens according to claim11.
 17. A contact lens according to claim
 12. 18. A contact lensaccording to claim
 13. 19. A contact lens according to claim
 14. 20. Acontact lens according to claim 15.